I have ordered those before. The first time they came with clips to connect them side by side, but they opened oddly in that fashion. What otherwise appeared to be the lid is what attached to the next case, and the only way that makes sense to open them is to drop the bottom, as turning them over makes opening awkward (it's just the way the latch is, and the bottom is difficult to pull up).

The second time I ordered exactly that, they came without the means to connect them. So be aware of that possibility.

The thing I like the most about the ones which do connect is being able to label my rechargeable batteries with type and priority. It helps keep them better organized, and helps keep track of the newer and older batteries (and more recently charged).